5.5 UE-initiated Resource Request and Release

23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS

This clause is related to the case when UE-initiated resource request and release is supported, and it is utilized for the PMIP-based S5/S8 traffic flow aggregates.

In the non-roaming case, vPCRF will not be involved.

Figure 5.5-1: UE-initiated resource request/release with PMIP-based S5/S8

This procedure applies to the Non-Roaming (Figure 4.2.1-1), Roaming (Figure 4.2.1-2) and Local Breakout (Figure 4.2.3-4) cases. For the Roaming and Local Breakout cases, the vPCRF forwards messages between the Serving GW and the hPCRF. In the Local Breakout case, the vPCRF forwards messages between the PDN GW and the hPCRF.

The optional interaction steps between the gateways and the PCRF in the procedures in Figure 5.5-1 only occur if dynamic policy provisioning is deployed. Otherwise policy may be statically configured with the gateway.

A.1. The Serving GW initiates the Gateway Control and QoS Policy Rules Request Procedure as specified in TS 23.203 [19]. The Serving GW provides the content of the Traffic Aggregate Description (TAD) and the requested QoS change to the PCRF as an Event Report. The PCRF makes a PCC decision as a result of the Gateway Control and QoS policy request and provides the updated QoS Rules to the Serving GW. The PCRF declaration of support for the extended TFT filter format is a precondition for the Serving GW accepting and forwarding TAD filters that use the extended TFT filter format to the PCRF.

Steps between A.1 and B.1 are described in TS 23.401 [4], clauses 5.4.1, 5.4.2 and 5.4.3 for resource allocation/modification or clause 5.4.4.1 for resource deactivation. Based on the QoS policy rules, the Serving GW decides whether to initiate a dedicated resource allocation activation or dedicated resource allocation modification (with or without QoS update).The Serving GW uses this QoS policy to assign the EPS Bearer QoS, i.e. it assigns the values to the bearer level QoS parameters (excluding AMBR); see clause 4.7.3 of TS 23.401 [4] and sends the appropriate message to the MME.

B.1. The Serving GW indicates to the PCRF whether the requested QoS Policy Rules Provision could be enforced or not and indicates User Location Information and/or UE Time Zone Information to the PCRF as an Event Report if the corresponding event trigger is set. This completes the GW Control and QoS Rules Provision procedure started in step A.1.

B.2. The PCRF initiates the Policy and Charging Rules Provision Procedure as specified in TS 23.203 [19] to update the PCC rules in the PDN GW.

NOTE: Step B.2 may be performed in parallel with Steps A.1‑B1 if acknowledgement of resource allocation is not required at the PCRF to update PCC rules in PCEF. For details please refer to TS 23.203 [19].